2025Activity reportProject-TeamMFX
RNSR: 201822795D- Research center Inria Centre at Université de Lorraine
- In partnership with:Université de Lorraine
- Team name: Matter from Graphics
- In collaboration with:Laboratoire lorrain de recherche en informatique et ses applications (LORIA)
Creation of the Project-Team: 2019 November 01
Each year, Inria research teams publish an Activity Report presenting their work and results over the reporting period. These reports follow a common structure, with some optional sections depending on the specific team. They typically begin by outlining the overall objectives and research programme, including the main research themes, goals, and methodological approaches. They also describe the application domains targeted by the team, highlighting the scientific or societal contexts in which their work is situated.
The reports then present the highlights of the year, covering major scientific achievements, software developments, or teaching contributions. When relevant, they include sections on software, platforms, and open data, detailing the tools developed and how they are shared. A substantial part is dedicated to new results, where scientific contributions are described in detail, often with subsections specifying participants and associated keywords.
Finally, the Activity Report addresses funding, contracts, partnerships, and collaborations at various levels, from industrial agreements to international cooperations. It also covers dissemination and teaching activities, such as participation in scientific events, outreach, and supervision. The document concludes with a presentation of scientific production, including major publications and those produced during the year.
Keywords
Computer Science and Digital Science
- A5.5.1. Geometrical modeling
- A5.5.2. Rendering
- A8.3. Geometry, Topology
Other Research Topics and Application Domains
- B5.7. 3D printing
1 Team members, visitors, external collaborators
Research Scientists
- Sylvain Lefebvre [Team leader, INRIA, Senior Researcher, HDR]
- Xavier Chermain [INRIA, ISFP]
- Jonas Martinez Bayona [INRIA, Researcher]
- Camille Schreck [INRIA, ISFP]
Faculty Members
- Cedric Zanni [UL, Associate Professor Delegation, from Sep 2025]
- Cedric Zanni [UL, Associate Professor, until Aug 2025]
Post-Doctoral Fellows
- Eric Garner [INRIA, Post-Doctoral Fellow, until Nov 2025]
- Charline Grenier [UL, Post-Doctoral Fellow]
- Rebekka Vaarum Woldseth [INRIA, Post-Doctoral Fellow]
PhD Students
- Giovanni Cocco [INRIA]
- Marco Freire [UL, ATER, until Aug 2025]
- Clément Magniez [UL, from Apr 2025]
- Luis Mollericon Titirico [INRIA]
- Damien Simon [INRIA, from Jul 2025]
- Damien Simon [INRIA, from Apr 2025 until Jun 2025]
Technical Staff
- Vincent Belle [INRIA, Engineer]
- Pierre-Alexandre Hugron [INRIA, Engineer, until Feb 2025]
- Lucas Ochocinski [INRIA, Engineer]
- Yamil Salim Perchy Bocanegra [INRIA, Engineer]
Interns and Apprentices
- Alois Lemaux [UL, Intern, until Jun 2025]
- Jolan Muneaux [UL, Intern, from Sep 2025]
- Antonin Rousseau [INRIA, Intern, from Mar 2025 until Sep 2025]
- Thibaut Vebret [UL, from Sep 2025]
Administrative Assistants
- Antoinette Courrier [CNRS]
- Emmanuelle Deschamps [INRIA]
- Gallown Nizard [UL]
- Cecilia Olivier [INRIA]
2 Overall objectives
Digital fabrication has had a profound impact on most industries. It allows complex products to be modeled in Computer Assisted Design (CAD) software and then sent to Computer-Aided Manufacturing (CAM) devices that physically produce the products. Typical CAM devices are computer-controlled lathes and milling machines that are ubiquitous in mass-production chains, along with injection molding and assembly robots. The design of a new product requires a large pool of expertise consisting of highly skilled engineers and technicians at all stages: design, CAD modeling, fabrication, and assembly chains.
With CAM technologies, the advent of Additive Manufacturing (AM) (i.e., 3D printing) and powerful and inexpensive computational resources let us envision a different scenario. In particular, these technologies excel where traditional approaches find their limitations:
- Parts with complex geometry can be fabricated in a single production run, and in most situations, the cost is not significantly impacted by the geometric complexity.
- The cost-per-unit for fabricating an object is constant and significantly lower than producing a small series of objects with traditional means. However, it is not competitive on a mass-production scale where the cost-per-unit decreases as the number of produced units increases.
- The machine setup is largely independent of the object being fabricated, and thus, these technologies can be made available through generic 3D printing companies and online print services. Additionally, the machines are significantly easier to operate than traditional fabrication means. This makes them accessible to the general public and well-suited for rapid design iterations and prototyping.
Consequently, designing and producing parts with short development cycles becomes possible: physical objects are uniquely and efficiently fabricated from digital models. Each object can be personalized for a specific use or customer. The core difficulty in this context lies in how to model the parts, and this remains a significant obstacle as functional and manufacturability constraints have to be enforced. By functional constraint, we refer here to some desired behavior in terms of rigidity, weight, balance, porosity, or other physical properties. This is especially important as AM allows the fabrication of extremely complex shapes, the scales of which vary from a few microns to a few meters. All this pushes AM well beyond traditional means of production and enables the concept of metamaterials; materials where parameterized microstructures change the behavior of a base shape fabricated from a single material.
Exploiting this capability turns the modeling difficulties into acute challenges. With such a quantity of details modeling becomes intractable, and specifying the geometry with standard tools becomes daunting, even for experts. Besides, these details have to interact in subtle and specific ways to achieve the final functionality (e.g., flexibility, porosity) while enforcing fabrication constraints. On the process planning side (i.e., the set of computations turning the part into printing instructions), large parts filled with microstructures, porosities, and intricate multi-scale details quickly lead to huge data sets and numerical issues.
We aim to develop novel approaches enabling experts and practitioners to exploit AM's advantages fully. We aim to achieve this by developing novel algorithms automatically synthesizing or completing designs with functional details. We consider the entire chain, from modeling to geometry processing, to optimize 3D printer instructions.
3 Research program
We focus on the computational aspects of shape modeling and processing for digital fabrication: dealing with shape complexity, revisiting design and customization of existing parts given the novel possibilities afforded by AM, and providing a stronger integration between modeling and the capabilities of the target processes.
We tackle the following challenges:
- develop novel shape synthesis and shape completion algorithms that can help users model shapes with features in the scale of microns to meters while following functional, structural, geometric, and fabrication requirements;
- propose methodologies to help expert designers describe shapes and designs that can later be customized and adapted to different use cases;
- develop novel algorithms to adapt and prepare complex designs for fabrication with a given technology, including the possibility to modify aspects of the design while preserving its functionality;
- develop novel techniques to unlock the full potential of fabrication processes, improving their versatility in terms of feasible shapes as well as their capabilities in terms of accuracy and quality of deposition;
- develop novel shape representations, data-structures, visualization, and interaction techniques to support the integration of our approaches into a single, unified software framework that covers the full chain from modeling to printing instructions;
- integrate novel capabilities enabled by advances in additive manufacturing processes and materials in the modeling and processing chains, in particular regarding the use of functional materials (e.g., piezoelectric, conductive, shrinkable).
Our approach is to cast a holistic view on the challenges above by considering modeling and fabrication as a single, unified process. Thus, the modeling techniques we seek to develop will consider the geometric constraints imposed by the manufacturing processes (minimal thickness, overhang angles, trapped material) and the desired object functionality (rigidity, porosity). To allow for the modeling of complex shapes and adapt the same initial design to different technologies, we propose developing techniques that can automatically synthesize functional details within parts. At the same time, we will explore ways to increase the manufacturing processes' versatility through algorithms capable of exploiting additional degrees of freedom, introducing new capabilities, and improving part accuracy.
Our research program is organized along with three main research directions. The first focuses on the automatic synthesis of shapes with intricate multi-scale geometries conforming to the constraints of additive manufacturing technologies. The second direction considers geometric and algorithmic techniques for the actual fabrication of the modeled object. We aim to further improve the manufacturing processes' capabilities with novel deposition strategies. The third direction focuses on computational design algorithms to help model parts with a gradient of properties and help customize existing designs for their reuse.
These three research directions interact strongly and cross-pollinate: e.g., novel possibilities in manufacturing unlock novel possibilities in terms of shapes that can be synthesized. Stronger synthesis methods allow for further customization.
4 Application domains
4.1 Digital Manufacturing
Our work addresses generic challenges related to fabrication and can thus be applied in a wide variety of contexts. Our aim is first and foremost to develop the algorithms that will allow variously industrial sectors to benefit more strongly from the potential of AM. To enable this, we seek collaborations with crucial industry partners developing software and AM systems for a variety of processes and materials that are of interest to specific sectors (e.g., dental, prosthetic, automotive, aerospace).
4.2 Medical Applications
To allow for faster transfer of our techniques and unlock novel applications, we actively seek to develop applications in the medical sector. In particular, we are involved in a project around the design of orthoses, which explores how our research on elasticity control through microstructure geometries can be specifically applied to the medical sector.
5 Social and environmental responsibility
5.1 Footprint of research activities
Our environmental footprint is limited. We use various products for 3D printing but in small quantities, and have put in place all required measures for recycling and disposal.
5.2 Impact of research results
We make our software IceSL freely available to the public and have continued this year to document its features, organize tutorials and presentations (e.g. at 3DPrint Paris), as well as animate the IceSL community through the official mailing list. With this, we hope to encourage adoption of our research and maximize its impact, in particular by encouraging its use within the maker communities.
A longer-term strategy of the team is to help develop potential uses of our technique in different fields. This is for instance a key motivation for our participation in the DORNELL challenge, that seeks to improve devices helping people with mobility impairments.
The exploratory action AEX CONTINUA emphasizes applications using 3D printing technology to construct large-scale structures to safeguard marine habitats vulnerable to rising temperatures due to global warming. We have an ongoing collaboration with researchers of CNRS (Serge Planes) and ENS Ulm (Emmanuel Dormy) that seeks to tackle this particular problem in the case of coral reefs.
6 Highlights of the year
6.1 Awards
- Atomizer 14 received an Honorable Mention at the Symposium on Geometry Processing (SGP) 2025.
Atomizer Honorable Mention
Figure 1: Atomizer Honorable Mention - Clément Magniez, PhD student within the team, received the best paper award and won the ShaderToy competition at the national Computer Graphics conference Journées Française de l'Informatique Graphique 2025
7 Latest software developments, platforms, open data
7.1 Latest software developments
7.1.1 IceSL
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Keyword:
Additive manufacturing
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Scientific Description:
IceSL is the software developed within MFX, that serves as a research platform, a showcase of our research results, a test bed for comparisons and a vector of collaborations with both academic and industry partners. The software is freely available both as a desktop (Windows/Linux) and as an online version.
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Functional Description:
IceSL allows users to model complex shapes through CSG boolean operations. Objects can be directly prepared and sent to a 3D printer for fabrication, without the need to compute an intermediate 3D mesh.
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News of the Year:
IceSL's current stable version is 2.5.4. It has accumulated more than 180k downloads between stable/beta and Windows/Linux releases. Linux/Windows share of downloads is 30% / 70% respectively. The IceSL web portal gathers all useful resources (doc, download links, features, etc.), as well as our online tools. The web slicer and web printer are used, respectively, 23 and 20 times per day on average. The online modeler has created and sliced more than 300 geometries since its inception on February 2024.
Important milestones throughout 2025 for IceSL are, (1) a methodology and implementation (through plugins) that minimizes cross-contamination in multi-material prints, (2) a complete CI/CD pipeline attached to all IceSL components (desktop – windows and linux – and online builds), and, (3) refined implementation of curved-slicing and refactor of user parameters (video tutorial included).
- URL:
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Contact:
Sylvain Lefebvre
7.1.2 Silice
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Name:
Silice
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Keywords:
FPGA, Programming
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Functional Description:
Silice makes it possible to write algorithms for FPGAs in the same way we write them for processors: defining sequences of operations, subroutines that can be called, and using control flow statements such as while and break. At the same time, Silice lets you fully exploit the parallelism and niceties of FPGA architectures, describing operations and algorithms that run in parallel and are always active, as well as pipelines. Silice remains close to the hardware: nothing gets obfuscated away. When writing an algorithm you are in control of what happens at which clock cycle, with predictable rules for flow control. Clock domains are exposed. In fact, Silice compiles to and inter-operates with Verilog: you can directly instantiate and bind with existing modules.
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Release Contributions:
2021 version.
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News of the Year:
This year Silice continued to develop and mature. The latest features were merged from the development branch to master, with several improvements and bug fixes. The installation was upgraded, including switching to YoWASP under MinGW / Windows systems, facilitating the use of Silice in classrooms. ASIC projects submitted to TinyTapeout shuttles 7 and 8 were confirmed as working, validating 3 different on-chip designs.
- URL:
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Contact:
Sylvain Lefebvre
7.2 New platforms
Participants: Pierre-Alexandre Hugron, Salim Perchy, Vincent Belle, Lucas Ochocinski.
MFX continued its presence and participation within the Creativ'Lab, which is operated by Loria and funded by Inria, Loria, CNRS and Région Grand Est.
Platform reorganization Following the arrival of new PhDs, Vincent Belle completely reorganized the filament printing lab within the Creativ'Lab. He reassessed which machines were being actively used in the workshop, and stored others to free necessary space.
All the Material storage were reviewed as well, in order to cut the unused material and limit wastage. Additionally, the filament recycler has been re-enabled in order to explore material refurbishing capabilities.
Non-planar printing Following the non-planar work last year, a new machine has been designed, alongside the firmware and the kinematic, to further the development of non planar slicing softwares. This machine has been then upgraded to enable a wider range of non planar printing. These upgrades were then added to a github repository in order to widespread open sourced the project for the maker community. It was also carried by a research paper, which was presented at SCF 2025 in Boston: “Towards Accessible Non-Planar FFF Using Triple Z-Axis Kinematics”, written by Giovanni Coco et al. here
Maintenance and upgrades All the printer's maintenance has been performed. All filament printers have been maintained and properly cared for (minor repairs, Firmware updates, lubrications, cleaning nozzle, beds, chassis, belt adjustment, axis maintenance). All resin printers have been maintained as well (film replacement, filter checks, screws control).
Our clay printer and laser cutter also had maintenance operations performed.
The tensile strength machine has been repaired and is now fully operational. A faulty sensor has been changed and calibrations have been performed.
Work space safety We are continuously focusing on improving the safety of operation in the printing rooms. In 2025, Sylvain Lefebvre and Vincent Belle followed an electrical safety protocols formation to operate around low voltage machinery: “Habilitation Électrique pour des opérations simples ou d'ordre non électrique BS, BE - ERTF:.”Xavier Chermain attended a fire safety training.
Scientific public outreach With the aim of sharing the knowledge developed within the team, the MFX printing workshops were presented multiple times during the year:
- Inria maker network in April,
- researchers in July,
- University administration (rectorate) in September,
- intern in November.
7.3 Open data
8 New results
8.1 Atomizer: Beyond Non-Planar Slicing for Fused Filament Fabrication
Participants: Xavier Chermain, Giovanni Cocco, Cedric Zanni, Eric Garner, Pierre-Alexandre Hugron, Sylvain Lefebvre.
We introduced Atomizer, a toolpath generation method for fused filament fabrication (FFF) that moves beyond the traditional layer-based slicing paradigm. Instead of generating trajectories from a sequence of planar or non-planar slices, Atomizer distributes oriented volumetric elements (“atoms”) inside the object volume, optimizing their spacing and orientation while remaining faithful to the target geometry. A fabrication plan is then produced by computing a collision-free traversal of these atoms, yielding toolpaths that conform to curved surfaces, fill narrow features down to a single path, and enable new deposition strategies such as locally printing vertical structures before transitioning elsewhere. The approach also supports appearance-driven constraints, enabling anisotropic surface finishes on curved geometries.
This work was published in Computer Graphics Forum (Proceedings of SGP 2025) 14 and presented at the Symposium on Geometry Processing 2025 by Xavier Chermain .
Atomizer reduces geometric deviations.
8.2 Double QuickCurve: revisiting 3-axis non-planar 3D printing
Participants: Emilio Ottonello, Pierre-Alexandre Hugron, Alberto Parmiggiani, Sylvain Lefebvre.
In 2025 we continued our efforts to improve and provide efficient techniques compatible with current slicing technologies, while simultaneously exploring entirely novel technique such as Atomizer above. Double QuickCurve is the latest entry in this line of research ; it results from a collaboration with IIT Italy (Istituto Italiano di Tecnologia). The main originality is to optimize for two (non-planar) slicing surfaces, one aligning with top surfaces, one aligning with bottom surfaces. This gives rise by interpolation to a family of slicing surfaces, then used to extract curved deposition trajectories.
This result was published as a EUROGRAPHICS short paper in 2025 16 and is fully integrated in our slicing software IceSL.
Double QuickCurve is an efficient approach to produce non-planar slices.
8.3 Towards Accessible Non-Planar FFF Using Triple Z-Axis Kinematics
Participants: Giovanni Cocco, Eric Garner, Vincent Belle, Cédric Zanni, Xavier Chermain.
We proposed a low-cost approach to non-planar fused filament fabrication (FFF) that makes 5-axis printing more accessible on standard desktop machines. The key idea is to tilt the print bed using three independently actuated Z-axes (“3Z”), requiring only minimal hardware modifications (notably extending rails and bed screws), while avoiding the cost and complexity of robotic arms. We derive the 3Z kinematic model with closed-form solutions and provide an open-source Python implementation that maps 3D toolpaths to machine commands. We further analyze the achievable build volume, sensitivity to mechanical tolerances, and practical aspects of trajectory interpolation in machine space, and we validate the approach experimentally with non-planar prints reaching bed tilts up to 30 degrees.
This work was published at the ACM Symposium on Computational Fabrication (SCF '25) 15 and presented at SCF 2025 (Cambridge, MA, USA) by Giovanni Cocco and Vincent Belle .
Three independent Z-axes printer.
8.4 Improving Curl Noise
Participants: Andreas Bærentzen, Jonàs Martínez, Jeppe Revall Frisvad, Sylvain Lefebvre.
In collaboration with DTU (Technical University of Denmark) researchers, we introduced a divergence-free nD vector noise defined as the n-dimensional cross product of the gradients of n - 1 noise functions. Our method enables precise integration and extends to new settings by substituting noise functions with implicit surfaces, (hyper)surfaces, or custom functions. We demonstrated applications including image warping, surface texturing, noise bounded by implicit surfaces, anisotropic curl-noise, and high-dimensional point jittering up to 7D.
This work was published in the conference proceedings of Siggraph Asia 2025 17.
Overview of Curl Noise Jittering
8.5 Cage-based deformation of field functions
Participants: Charline Grenier, Kévin Trancho, Clément Magniez, Cédric Zanni, Loïc Barthe.
Implicit geometry is a popular representation for shape modelling. It provides several interesting properties, such as infinite resolution, continuity and smooth blending. However, implicit surfaces are difficult to deform as deformations need to be invertible. They are in general restricted to linear representations or more advanced translation-based deformations. We propose a method that adapts cage-based deformation to implicit surfaces while handling self-intersections in the deformed space.
This work was presented as a Eurographics poster 19.
8.6 Improving spatial domain repetition of implicit surfaces
Participants: Clément Magniez, Cédric Zanni.
Implicit surfaces offer distinct advantages over traditional boundary representations, including infinite resolution, low memory footprint, smooth geometry by construction, and support for non-destructive modeling. In this work, we introduce a method for localizing geometric detail in a way that preserves the mathematical properties required for accurate and efficient rendering using sphere tracing. Our contributions include novel procedural modeling techniques that expand the range of repetition patterns achievable in implicit surfaces; an interpolation-based approach that maintains field correctness while remaining computationally efficient; and a cache-based acceleration strategy that significantly improves the rendering performance of domain-repeated implicit geometries.
This work was presented at Journées Française de l'Informatique Graphique (Edition 2025) where it received the best paper award.
8.7 3D printed capacitive sensing
Participants: Jose Eduardo Aguilar-Segovia, Fabien Grzeskowiak, Maxime Manzano, Sylvain Guégan, Ronan Le Breton, Alice Farhi-Rivasseau, Sylvain Lefebvre, Marie Babel.
We explore augmenting parts with sensors fabricated in-situ, i.e. directly within the part, using functional materials deposited at the same time as the structural materials. However, achieving this goal at low cost remains challenging. This work investigates the design of parametric capacitive sensors that can be embedded in complex designs. The sensors can be manufactured on multi-material extrusion 3D printers using commercially available non-conductive and conductive thermoplastic polyurethane.
The results of this project are published in the international journal IEEE Sensors12. This is joint work lead by the RAINBOW team, the LGCGM and the MFX team. This focuses on challenges relating to the PhD thesis of Eduardo Aguilar-Segovia and the DORNELL Inria challenge.
A functional joystick printed as a single multi-material part.
9 Bilateral contracts and grants with industry
9.1 Bilateral contracts with industry
Partnership with AddUp
Participants: Sylvain Lefebvre.
- Company: AddUp.
- Duration: Started in 2019.
- Abstract: AddUp is a French manufacturer of metal 3D printers for high-end industrial applications. We announced during FormNext 2019 (November) a partnership towards the creation of new software technologies. This partnership continued to develop in 2025 with the Master research internship of Antonin Rousseau, funded by AddUp within MFX.
Other industrial partnership
Participants: Sylvain Lefebvre.
- Company: S.A.M. Link
- Duration: Started in 2023.
- Abstract: The startup S.A.M. Signature Authentification des Matériaux develops additive manufacturing solutions for authentication, security and traceability. Sylvain Lefebvre is scientific advisor for the startup in the context of a technology transfer. In 2025 the startup received two prizes: Prix Innovation & Meilleure Avancée Technologique, 3DPRINT Lyon (June 2025); Prix de la Meilleure Avancée Technologique, Conférence France Additive (July 2025).
10 Partnerships and cooperations
10.1 International research visitors
10.1.1 Visits of international scientists
Andreas Bærentzen and Jeppe Frisvad
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Status
Researchers.
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Institution of origin:
Technical University of Denmark (DTU).
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Country:
Denmark.
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Dates:
November 27-28.
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Context of the visit:
Joint work on curl noise, preparing a funding proposal.
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Mobility program/type of mobility:
Research visit, seminar.
10.1.2 Visits to international teams
Giovanni Cocco and Vincent Belle
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Visited institution:
Boston University.
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Country:
USA.
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Dates:
November 17-19.
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Context of the visit:
Collaboration with Edward Chien’s team at Boston University.
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Mobility program/type of mobility:
Research stay.
10.2 European initiatives
10.2.1 Horizon Europe
KARST
KARST project on cordis.europa.eu
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Title:
KARST: Predicting flow and transport in complex Karst systems
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Duration:
From May 1, 2023 to April 30, 2029
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Partners:
- Institut National De Recherche En Informatique Et Automatique (Inria), France
- Agencia Estatal Consejo Superior De Investigaciones Cientificas (CSIC), Spain
- Universite De Neuchatel (UNINE), Switzerland
- Simon Fraser University (SFU), Canada
- IFP Energies nouvelles (IFPEN), France
- Univerza V Ljubljani (UL), Slovenia
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Inria contact:
Sylvain Lefevre
- Coordinator:
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Summary:
Karst aquifers are a treasure and a threat: while up to 25% of the world population depends on them for drinking water, they also have capabilities for extremely fast conduction of water and contaminants. In the light of climate change, we need to prepare for extreme flooding and understand the consequences for karst aquifers. Despite their socio-economic importance, decades of research, and high-profile disasters, karst structures and processes remain notoriously difficult to assess. Because of the complexity of karst and its lack of accessibility, the foundations of flow and transport modeling in karst systems are weak. Key phenomena related to extreme events such as flash floods and heavy tails in tracer recovery are still beyond current modeling capabilities.
KARST will establish the next generation of coupled stochastic modeling frameworks to predict karst processes, assess the vulnerability of karst aquifers, and forecast their response to extreme events. Our approach will bridge structures and processes on all scales, far beyond the capabilities of current theories and computer simulations. This will be achieved by targeting three key objec- tives: (i) Identification and quantification of flow and transport dynamics at the conduit scale. (ii) Characterization and modeling of karst network structure at the catchment scale. (iii) Derivation of a new upscaled approach to predict karst processes at different resolution scales. Together, this will result in an unprecedented multiscale modeling framework for the prediction of flow and transport in karst.
Solving this long-standing problem is possible thanks to the synergy of the KARST PI team combining the set of skills and knowledge (hydrogeology, physics, mathematics) required to make a ground-breaking step in this field. Beyond that, the new approach is expected to impact other real-world systems in medicine (capillary networks), neuroscience (brain microcirculation) or glaciology (meltwater flow in glaciers).
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Activity in 2025:
In the context of the KARST project, we designed and printed around 90 parts in different materials. This level of production is more important than the previous year (almost x3), aiming at improving the fluid testing installation assembled by the KARST team at IFPEN (Paris). We work closely with the partners of the KARST project to find a way to enhance the design of each cave and moreover to increase the production speed even if the parts are totally handmade and cannot be automatized. The printed parts are modular and can be rapidly adjusted to iterate as the installation is refined.
Two workshops were organized and attended for the purpose of project coordination, sharing of results and future work preparation. These workshops also provided context on many topics external to computer science (geology, network quantification):
- KARST Workshop Barcelona, Spain - 03-05 June, 2025. (The works were presented by Salim Perchy)
- KARST Workshop Rueil-Malmaison, France - 12-14 November, 2025. (The works were presented by Lucas Ochocinski)
10.3 National initiatives
ANR ANISO
Participants: Xavier Chermain, Sylvain Lefebvre, Giovanni Cocco, Vincent Belle, Eric Garner.
- Acronym: ANISO.
- Title: Anisotropic Appearance Fabrication With High-Resolution and Spatially Varying Orientations
- Duration: October 2024 – October 2028.
- Coordinator: Xavier Chermain.
- Abstract: Brushed finishes are widely used in architecture, large and small appliances, etc. ANISO aims to develop new digital and manufacturing technologies to produce customized and innovative anisotropic surface finishes. The aim is to go beyond unidirectional and circular surface finishes by allowing the designer to choose the brushing orientation for all surface positions. This freedom makes it possible to design customized and complex anisotropic appearances. Fabricating anisotropic appearances on 3D surfaces with arbitrary, spatially varying, high-definition orientations remains an open problem. We target glossy materials: metals (e.g., aluminum, silver, and gold), plastics (e.g., PETG and PLA), and glass. ANISO’s key idea is to use manufacturing processes that directly produce anisotropic surface roughness: Fused Filament Fabrication (FFF) and surface brushing. We plan to develop an algorithm that generates orientable, space-filling trajectories to control the direction of anisotropy at each point. Open-source software will be developed to interactively design and visualize anisotropic appearances with spatially variable directions to democratize the manufacture of this type of appearance. ANISO will enable Industry 4.0 to customize surface finishes and make them unique. Customization will be achieved using a single material that does not require paint or chemicals, making recycling easier. In addition, the surface finish of injection molding could be impacted by ANISO, enabling Industry 4.0 to produce customized parts and unique visuals on a large scale.
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Activity in 2025:
We hired Vincent Belle as a research engineer for the project in November. Eric Garner was hired as a postdoctoral researcher from June to November. As part of the ANISO project, we published two articles 14, 15. Atomizer 14 was presented by Xavier Chermain at the Symposium on Geometry Processing in Bilbao, and the 3Z kinematic model 15 was presented by Giovanni Cocco and Vincent Belle at the Symposium on Computational Fabrication in Boston.
Région Grand Est – ANISO (regional funding support)
Participants: Xavier Chermain, Sylvain Lefebvre, Giovanni Cocco, Vincent Belle, Eric Garner.
- Funding body: Région Grand Est.
- Project: ANISO (support to the ANR ANISO project).
- Amount: 58 500 euros.
- Period: 2025 – 2028
- Summary: This regional funding supported the acceleration of the ANISO research program on the fabrication of customized anisotropic surface finishes with high-resolution and spatially varying orientations. The support contributed to strengthening the project's engineering capacity through human resources.
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Activity in 2025:
50% of the PhD funding of Giovanni Cocco is supported by this grant.
ANR MultiForm
Participants: Cédric Zanni.
- Acronym: MultiForm.
- Title: Multivariate Implicit Function Deformation.
- Duration: 2023-2026.
- Coordinator: Loïc Barthe.
- Partners: Université Paul Sabatier, Ecole Polytechnique
- Abstract: This project aims at developing theoretical aspects of 3D field functions in computer graphics: 3D animation and the representation of complex multi-material virtual objects. An innovative aspect is the study of multivalued field functions and their deformations in this context. Practically, it aims at providing more efficient new solutions for both the deformation of animated 3D objects with collisions, and the representation of complex structures composed of several materials such as organic (muscular, bones, soft tissues) or liquid/solid structures (as a lava flow). The final goal being the deformations with collisions of these complex structures.
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Activity in 2025:
We hired Clément Magniez as a PhD candidate and host Charline Grenier as a postdoctoral researcher. Ongoing work includes free-form deformation of implicit surfaces and improved control for procedural implicit surfaces.
10.3.1 Inria
Inria Exploratory Action CONTINUA
Participants: Jonàs Martínez, Luis Mollericon.
- Acronym: AEx CONTINUA.
- Title: Continuous deposition of paste-like materials.
- Duration: 2022-2026.
- Coordinator: Jonàs Martínez.
- Abstract: Additive Manufacturing (AM) using paste-like materials such as clay or silicon enables the construction of large-scale structures but poses significant challenges for intricate geometries. During the manufacturing process, there is a heightened risk of structural collapse under gravity, leading to defects caused by repeated interruptions in extrusion flow. Previous efforts have primarily focused on simpler structures, failing to harness the full potential of AM. AEx CONTINUA aims to explore the realm of manufacturable deposition paths to empower the Additive Manufacturing of large-scale, complex structures, addressing the inherent challenges and pushing the boundaries of AM capabilities.
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Activity in 2025:
We had an article accepted to the CMAME journal for publication in 2026, synthesizing the doctoral work of Luis Mollericon Titirico in collaboration with Ole Sigmund from DTU, Denmark.
Inria Challenge DORNELL
Participants: Sylvain Lefebvre, Pierre-Alexandre Hugron, Camille Schreck, David Jourdan, Vincent Belle.
- Acronym: DORNELL
- Title: A multimodal, shapeable haptic handle for mobility assistance of people with disabilities.
- Duration: 2022-2026.
- Coordinator: Marie Babel.
- Partners: Inria MFX, POTIOC.
- Abstract: While technology helps people to compensate for a broad set of mobility impairments, visual perception and/or cognitive deficiencies still significantly affect their ability to move safely and easily. DORNELL proposes an innovative multisensory, multimodal, smart haptic handle that can be easily plugged onto a wide range of mobility aids. Specifically fabricated to fit the needs of a person, it provides a wide set of tactile sensations in a portable and plug-and-play format – bringing haptics in assistive technologies all at once.
- Activity in 2025:
11 Dissemination
11.1 Promoting scientific activities
11.1.1 Scientific events: selection
Xavier Chermain participated in the ANR symposium “FABRIQUER DEMAIN, les systèmes productifs acteurs du changement” (6 May 2025, Arts et Métiers – ENSAM).
Chair of conference program committees
- Camille Schreck was co-chair of the Journées de l'AFIG 2025 best paper award (as YRF EGFR).
Member of the conference program committees
- Camille Schreck was a member of the international program committee of SIGGRAPH 2025.
- Sylvain Lefebvre was a member of the international program committee of SGP 2025.
Reviewer
- Camille Schreck was a reviewer for Computer Graphics International (CGI 2025), SIGGRAPH Asia 2025, and Computer Graphics Forum.
- Cédric Zanni was a reviewer for Computer Aided Design.
- Xavier Chermain was a reviewer for SIGGRAPH 2025 and SIGGRAPH Asia 2025.
- Jonàs Martínez was reviewer for SIGGRAPH 2025, SIGGRAPH Asia 2025, and Pacific Graphics 2025.
- Sylvain Lefebvre was a reviewer for SIGGRAPH 2025 and SIGGRAPH Asia 2025.
11.1.2 Journal
Reviewer - reviewing activities
- Xavier Chermain was a reviewer for Computer Graphics Forum (CGF).
- Giovanni Cocco was a reviewer for the Journal of Computer Graphics Techniques (JCGT).
- Jonàs Martínez was reviewer for TVCG, ACM ToG, and CAD journal.
11.1.3 Invited talks
- Marco Freire gave invited talks at the Informatique Géométrique et Graphique team, ICUBE (Strasbourg, France), at the G-Mod team, Laboratoire d'Informatique et Systèmes (Marseille, France), and at the ANIMA and MAVERICK team, Laboratoire Jean Kuntzmann / Centre Inria de l'UGA (Grenoble, France).
- Jonàs Martínez gave an invited talk at the MEMOCS workshop of 2025 with the theme "Methods in Metamaterials design: mathematical modelling, numerical techniques, experiments" (Arpino, Italy).
- Sylvain Lefebvre was invited to contribute a class during a summer school at CISM (Centre International de Science des Matériaux), Udine, Italy. The summer school was organized by a group of scientists ranging from physics, material science to geometry and Computer Graphics. More information can be found here
11.1.4 Leadership within the scientific community
Xavier Chermain mentored an early-career researcher from the GdR IG-RV in the preparation of ANR JCJC proposals.
11.1.5 Scientific expertise
Jonàs Martínez was code reviewer for the Graphics Replicability Stamp Initiative (GRSI).
11.1.6 Research administration
- Camille Schreck was member of the center comittee of the Inria center of the Lorraine University.
- Sylvain Lefebvre presided the Comité de Sélection for the professor recruitment at Ecole des Mines of Nancy, Lorraine University (PR27 Mines).
- Sylvain Lefebvre is a member of the Bureau du Comité des Projets of the Inria center.
11.2 Teaching - Supervision - Juries - Educational and pedagogical outreach
- License: Marco Freire, Programming projects, 15.7h ETD, Université de Lorraine, France
- License: Marco Freire, Introduction to discrete mathematics, 52.5h ETD, Université de Lorraine, France
- License: Marco Freire, Memory management, 10.7h ETD, Université de Lorraine, France
- License: Marco Freire, Graphical interfaces, 16h ETD, Université de Lorraine, France
- License : Cédric Zanni, Introduction to Computer Science, 31.5h ETD, L3, École des Mines de Nancy, France.
- Preparatory classes: Xavier Chermain , Nouveaux paradigmes de programmation et science des données, 64h ETD, prépa INP Nancy, France.
- Master: Camille Schreck, Introduction to 3D Graphics, 26h ETD, Telecom Nancy, France.
- Master: Camille Schreck, 3D Graphics and Parallelism, 12h ETD, ENSG Nancy, France.
- Master: Cédric Zanni, Software Engineering, 31.5h ETD, M1, École des Mines de Nancy, France.
- Master: Cédric Zanni, Introduction to C/C++, 54h ETD, M1, École des Mines de Nancy, France.
- Master: Cédric Zanni, Techniques for video game programming, 27h ETD, M1, École des Mines de Nancy, France.
- Master: Cédric Zanni, ARTEM Game Lab, 16h ETD, M1, École des Mines de Nancy, France.
- Master: Jonàs Martínez, AMA (GPU) course, 28h ETD, TELECOM Nancy, France.
- Master: Jonàs Martínez, Introduction to data parallelism, 36h ETD, Université de Lorraine, France.
- Master: Sylvain Lefebvre, Hardware design on FPGA, 12h ETD, Telecom Nancy, France.
11.2.1 Supervision
- Xavier Chermain co-supervised Giovanni Cocco (PhD student), and attended the professional training “Accompagner et encadrer une doctorante ou un doctorant”.
- Research initiation: Jolan Muneau . Sparse ternary and n-ary blobtree traversal. Advisor: Cédric Zanni - from 09/2025 to 06/2026.
- Xavier Chermain was the scientific supervisor of the in-lab project carried out by Thibaut Vebret (Mines Nancy – 2nd year): “Digital twin of a 5-axis fused-filament 3D printer”. The project was co-advised with Vincent Belle .
- Xavier Chermain supervised a team of five students from the preparatory school (prépa INP Nancy) on a software development project dedicated to the implementation of Phasor noise (procedural noise generation), including qualitative evaluation.
11.2.2 Juries
- Jonàs Martínez was examiner of the thesis of Siyuan He at ENPC, France.
- Sylvain Lefebvre was oponnent (rapporteur) on the PhD committee of Lubna Abu Rmaileh (Fraunhofer IGD, Norwegian University of Science and Technology (NTNU)).
11.2.3 Doctoral committees
- Sylvain Lefebvre was on the thesis advisory committee (comité de suivi de thèse) of Wilhem Barbier (Toulouse University)
- Sylvain Lefebvre was on the thesis advisory committee (comité de suivi de thèse) of Julien Soumier (Lorraine University).
- Sylvain Lefebvre was on the thesis advisory committee (comité de suivi de thèse) of Ghilain Bergeron (Lorraine University).
- Sylvain Lefebvre was on the thesis advisory committee (comité de suivi de thèse) of Andrea Tummolo (Rennes University).
- Jonàs Martínez was on the thesis advisory committee (comité de suivi de thèse) of Niels Cobat (Rennes University).
11.3 Popularization
11.3.1 Specific official responsibilities in science outreach structures
- Salim Perchy hosted the first Rencontre Thématique: Maker of 2025.
- This event was attended by a group of SED engineers (Service d'experimentation et développement) from several Inria centers.
- Several talks, demos and ateliers of fabrication and especially 3D printing were part of the program.
11.3.2 Productions (articles, videos, podcasts, serious games, ...)
- Video tutorial made by Salim Perchy about curved-slicing in IceSL
11.3.3 Participation in Live events
- IceSL training (June 2025) for Inria Montpellier. 2 Days; Modeling Functions & Printing Parameters. Conceived and animated by Salim Perchy.
11.3.4 Others science outreach relevant activities
- Salim Perchy attended and presented at the biannual meeting of ERC Synergy project Open KARTS. 5 days, June 2025
- Vincent Belle and Xavier Chermain were speakers at the CARDIE day (Cellule Académique Recherche Développement Innovation et Expérimentation du Rectorat) – 25 September 2025.
12 Scientific production
12.1 Major publications
- 1 articleOptimal discrete slicing.ACM Transactions on Graphics361February 2017, 1 - 16HALDOI
- 2 articleFast ray tracing of scale-invariant integral surfaces.Computer Graphics Forum406September 2021, 117-134HALDOI
- 3 articleBridging the Gap: Automated Steady Scaffoldings for 3D Printing.ACM Transactions on Graphics334July 2014, 98:1 - 98:10HALDOI
- 4 articleCurviSlicer: Slightly curved slicing for 3-axis printers.ACM Transactions on Graphics384August 2019, 1–11HALDOI
- 5 articleVariable-width contouring for additive manufacturing.ACM Transactions on Graphics394 (Proc. SIGGRAPH)July 2020HALDOI
- 6 articleBy-example synthesis of structurally sound patterns.ACM Transactions on Graphics2015HALDOI
- 7 articleProcedural Voronoi Foams for Additive Manufacturing.ACM Transactions on Graphics352016, 1 - 12HALDOI
- 8 articleStructure and appearance optimization for controllable shape design.ACM Transactions on Graphics346November 2015, 12HALDOI
- 9 articlePolyhedral Voronoi diagrams for additive manufacturing.ACM Transactions on Graphics374August 2018, 15HALDOI
- 10 articleOrthotropic k-nearest foams for additive manufacturing.ACM Transactions on Graphics364July 2017, 121:1--121:12HALDOI
- 11 articleFreely orientable microstructures for designing deformable 3D prints.ACM Transactions on GraphicsDecember 2020HALDOI
12.2 Publications of the year
International journals
International peer-reviewed conferences
Conferences without proceedings
Reports & preprints
Other scientific publications